Nasogastric (NG) intubation refers to the insertion of a plastic tube through the nose, past the throat and down into the stomach of a subject. NG intubation is a vital medical procedure and a common clinical procedure for both diagnostic and therapeutic purposes.
NG intubation is commonly performed “blindly” i.e. without any visual aid or indication. This places reliance on the user's skill and experience, and can lead to an erroneous insertion and misplacement of the NG tube. Studies have shown that these errors can result in a whole spectrum of thoracic and non-thoracic complications. For example, insertion of the NG tube into the subject's airways, or coiling or knotting of the NG tube during the insertion process, can cause complications, perforation and sometimes, even fatality.
To date, different bedside methods of localizing a NG tube within a subject have been developed. In particular, radiography is considered the gold standard for this purpose. However, it is not desirable to use radiography each time the NG tube needs to be inserted. Further, for long-term enteral feeding, the position of the tip of the tube is preferably determined prior to initiation of the tube feeding (which may be required at least three times a day). It is again not desirable to use radiography each time before tube feeding. This is because of the expenses involved in using radiography and the radiation exposure (which is especially an issue of concern when the subject is a child). Further, there may be regions where X-ray machines are not available.